.5 log reduction

Mar 18, 2006

I am trying to understand what a .5 log reduction. if 1 log means 10 copies what would .5 log mean?

Response from Dr. Holodniy

Here is a brief math lesson. Viral load can be expressed as absolute copy number or as log10 expression of absolute copy number. So, if you have 100,000 copies that is 5 log, 10,000 copies is 4 log, 1,000 is 3 log, 100 copies is 2 log and 10 copies is 1 log. Now, if you went from 100,000 to 10,000 copies that would be a 1 log reduction (5 - 4 log). If you went from 100,000 to 32,000 that would be a 0.5 log reduction (5 - 4.5 log) and so on.

This forum is designed for educational purposes only, and experts are not rendering medical, mental health, legal or other professional advice or services. If you have or suspect you may have a medical, mental health, legal or other problem that requires advice, consult your own caregiver, attorney or other qualified professional.

Experts appearing on this page are independent and are solely responsible for editing and fact-checking their material. Neither TheBody.com nor any advertiser is the publisher or speaker of posted visitors' questions or the experts' material.

The Body is a service of Remedy Health Media, LLC, 750 3rd Avenue, 6th Floor, New York, NY 10017. The Body and its logos are trademarks of Remedy Health Media, LLC, and its subsidiaries, which owns the copyright of The Body's homepage, topic pages, page designs and HTML code. General Disclaimer: The Body is designed for educational purposes only and is not engaged in rendering medical advice or professional services. The information provided through The Body should not be used for diagnosing or treating a health problem or a disease. It is not a substitute for professional care. If you have or suspect you may have a health problem, consult your health care provider.